U.S. patent application number 12/372398 was filed with the patent office on 2010-08-19 for radio access point location verification using gps location and radio environment data.
This patent application is currently assigned to CISCO TECHNOLOGY, INC.. Invention is credited to Jeffrey Antoline, Mickael Graham, Edward Haynes, Archie Hensley, Anton Okmyanskiy.
Application Number | 20100210280 12/372398 |
Document ID | / |
Family ID | 42102342 |
Filed Date | 2010-08-19 |
United States Patent
Application |
20100210280 |
Kind Code |
A1 |
Haynes; Edward ; et
al. |
August 19, 2010 |
Radio Access Point Location Verification Using GPS Location and
Radio Environment Data
Abstract
Techniques are provided to perform location verification of a
radio access point device such as femtocell. The radio access point
device is configured to receive signals from global positioning
system (GPS) satellite transmitters to produce GPS location data
representing a GPS location of the radio access point device. The
radio access point device is also configured to receive wireless
signals at one or more specified channels and to generate radio
environment data representing characteristics of received wireless
signals at the one or more specified channels in a vicinity of the
radio access point device. A comparison is made between the GPS
location data and reference GPS location data for an expected
location of the radio access point device. When the GPS location
data substantially matches the reference GPS location data,
operations of the radio access point device are enabled and the
radio environment data is stored to be used as reference radio
environment data for purposes of subsequent location verification
of the radio access point device. Subsequent location verifications
(such as on reboot) start with comparing radio environment data
with reference radio environment data and if a substantial match is
found, GPS location data does not need to be obtained. In the case
of substantial mismatch between radio environment data obtained at
reboot and the reference radio environment data, new GPS location
data is obtained and upon successful match to reference GPS
location data, the reference radio environment data is updated
based on the most recent radio environment data obtained by device.
In addition, a service-activated radio access point device performs
periodic radio network scans in order to update the reference radio
environment data if the new radio environment data differs from the
reference radio environment data outside of a tolerance range.
Inventors: |
Haynes; Edward; (Suwanee,
GA) ; Hensley; Archie; (Lawrenceville, GA) ;
Okmyanskiy; Anton; (Vancouver, CA) ; Antoline;
Jeffrey; (Roswell, GA) ; Graham; Mickael;
(Bellevue Hill, AU) |
Correspondence
Address: |
Edell, Shapiro & Finnan, LLC
1901 Research Boulevard
Rockville
MD
20850
US
|
Assignee: |
CISCO TECHNOLOGY, INC.
San Jose
CA
|
Family ID: |
42102342 |
Appl. No.: |
12/372398 |
Filed: |
February 17, 2009 |
Current U.S.
Class: |
455/456.1 |
Current CPC
Class: |
G01S 5/0242 20130101;
H04W 64/00 20130101; H04L 41/0806 20130101; G01S 5/0205 20130101;
H04W 88/08 20130101; H04W 64/003 20130101; H04W 84/045
20130101 |
Class at
Publication: |
455/456.1 |
International
Class: |
H04W 24/00 20090101
H04W024/00 |
Claims
1. A method comprising: at a radio access point device: receiving
signals from global positioning system (GPS) satellite transmitters
to produce GPS location data representing a GPS location of the
radio access point device; receiving wireless signals at one or
more specified channels and generating radio environment data
representing characteristics of received wireless signals in the
one or more channels in a vicinity of the radio access point
device; comparing the GPS location data with reference GPS location
data for an expected location of the radio access point device; and
when the GPS location data substantially matches the reference GPS
location data: enabling service of the radio access point device;
storing the radio environment data to be used as reference radio
environment data for purposes of subsequent location verification
of the radio access point device.
2. The method of claim 1, and further comprising a period of time
after enabling service of the radio access point device, receiving
wireless signals to generate updated radio environment data, and
adjusting the reference radio environment data based on the updated
radio environment data.
3. The method of claim 2, wherein receiving wireless signals to
generate updated radio environment data is performed on a periodic
basis.
4. The method of claim 2, wherein receiving wireless signals to
generate the updated radio environment data is performed in
response to a command from a control server.
5. The method of claim 1, wherein the radio environment data and
reference radio environment data comprise one or more selected from
the group of: an identifier of a cellular radio transceiver that
services a cell, a country code from a cellular signal, a network
code from a cellular signal, a frequency of a cellular signal, a
scrambling code of a cellular signal, a regional network controller
identifier for a cellular radio transceiver, a received power of a
signal from a cellular radio transceiver, an indication of
transmitted power level for a signal transmitted by a cellular
radio transceiver, and a transmission power loss derived from a
difference between transmitted signal power and received signal
power associated with a signal received from a cellular radio
transceiver.
6. The method of claim 5, wherein when the radio access point
device is subsequently rebooted, it subsequently boots up with
service disabled, and further comprising, receiving wireless
signals to generate radio environment data, comparing the radio
environment data with the reference radio environment data and
re-enabling service of the radio access point device when the radio
environment data substantially matches the reference radio
environment data.
7. The method of claim 6, wherein comparing the radio environment
data with the reference radio environment data comprises comparing
a portion of the radio environment data generated at reboot of the
radio access point device with a corresponding portion of the
reference radio environment data.
8. The method of claim 6, wherein when it is determined that the
radio environment data does not match the reference radio
environment data, further comprising receiving signals from GPS
satellite transmitters to produce GPS location data, comparing the
GPS location data with the reference GPS location data, re-enabling
service of the radio access point device when the GPS location data
substantially matches the reference GPS location data and updating
the reference radio environment data based on the radio environment
data obtained at reboot.
9. The method of claim 1, wherein storing and comparing are
performed at the radio access point device.
10. The method of claim 9, and further comprising receiving
provisioning data from a control server, wherein the provisioning
data includes the reference GPS location data for an expected
location of the radio access point device and tolerance data that
describes a tolerance range within with a match to the reference
GPS location and/or radio environment data is to be declared.
11. The method of claim 9, wherein when the radio access point
device is subsequently rebooted, it boots up with service disabled,
and further comprising, receiving wireless signals to generate
radio environment data, at the radio access point device comparing
the radio environment data with the reference radio environment
data and re-enabling service of the radio access point device when
the radio environment data substantially matches the reference
radio environment data.
12. The method of claim 1, wherein storing and comparing are
performed at a control server that is remote from said radio access
point device, and further comprising sending the GPS location data
and radio environment data from the radio access point device to
the control server, and wherein enabling service of the radio
access point device in response to a message received at the radio
access point device from the control server.
13. The method of claim 12, wherein when the radio access point
device is subsequently rebooted, it boots up with service disabled,
and further comprising, receiving wireless signals to generate
radio environment data, sending the radio environment data to the
control server, at the control server comparing the radio
environment data with the reference radio environment data, and
receiving a message from the control server that re-enables service
of the radio access point device when the control server determines
that the radio environment data substantially matches the reference
radio environment data.
14. The method of claim 13, wherein when the control server
determines that the radio environment data does not match the
reference radio environment data, further comprising receiving
signals from GPS satellite transmitters to produce GPS location
data, sending the GPS location data to the control server, at the
control server comparing the GPS location data with the reference
GPS location data, receiving a message at the radio access point
device from the control server that re-enables service of the radio
access point device when the control server determines that the GPS
location data matches the reference GPS location data, and at the
control server updating the reference radio environment data based
on the radio environment data obtained at reboot of the radio
access point device.
15. The method of claim 1, and further comprising periodically
repeating receiving signals from GPS satellite transmitters,
receiving wireless signals at the one or more specified channels to
generate radio environment data and comparing the GPS location data
with reference GPS location data in order to perform additional
location verifications even after service is enabled at the radio
access point device.
16. The method of claim 1, and further comprising periodically
repeating receiving signals from GPS satellite transmitters,
receiving wireless signals at the one or more specified channels to
generate radio environment data and comparing the GPS location data
with reference GPS location data until service for the RAP device
is eventually initially enabled.
17. An apparatus comprising: a radio transceiver unit configured to
transmit and receive wireless signals associated with a wireless
communication network to serve wireless mobile communication
devices that operate in the wireless communication network, wherein
the radio transceiver unit is configured to receive wireless
signals at one or more channels to generate radio environment data
representing characteristics of received wireless signals at the
one or more channels; a global positioning system (GPS) receiver
unit configured to receive GPS signals from multiple satellite
transmitters and to compute GPS location data representing a GPS
location from the GPS signals; a controller configured to connect
to the radio transceiver unit and the GPS receiver unit, wherein
the controller is configured to: prior to enabling service in the
wireless communication network for the first time, invoke the GPS
receiver unit to generate GPS location data for initial location
verification and invoke the radio transceiver unit to generate
radio environment data for purposes of subsequent location
verification after the apparatus is initially enabled for
service.
18. The apparatus of claim 17, wherein the radio transceiver unit
and the controller are configured to generate the radio environment
data comprising one or more selected from the group of: an
identifier of a cellular radio transceiver that services a cell, a
country code from a cellular signal, a network code from a cellular
signal, a frequency of a cellular signal, a scrambling code of a
received cellular signal, a regional network controller identifier
for a cellular radio transceiver, a received power of a signal from
a cellular radio transceiver, an indication of transmitted power
level for a signal transmitted by a cellular radio transceiver, and
a transmission power loss derived from a difference between
transmitted signal power and received signal power associated with
a signal received from a cellular radio transceiver.
19. The apparatus of claim 17, and further comprising a network
interface unit that is configured to transmit to and receive
messages from a control server over a data network, and wherein the
controller is further configured to receive provisioning data from
the control server, wherein the provisioning data includes
reference GPS location data for an expected location and tolerance
data that describes a tolerance range within with a match to the
reference GPS location data is to be declared, and wherein the
controller is further configured to compare the GPS location data
with the reference GPS location data and when the GPS location data
matches the reference GPS location data within the tolerance range,
enable service in the wireless communication network and store the
radio environment data to be used as reference radio environment
data for subsequent location verification.
20. The apparatus of claim 19, wherein when the apparatus is
subsequently rebooted and starts up with service disabled, and the
controller is configured to invoke the radio transceiver unit to
receive wireless signals and generate radio environment data, and
to compare the radio environment data with the reference radio
environment data and re-enable service of the apparatus when the
radio environment data substantially matches the reference radio
environment data.
21. The apparatus of claim 19, wherein the controller is further
configured to, a period of time after enabling service, invoke the
radio transceiver unit to receive wireless signals and generate
updated radio environment data, and adjust the reference radio
environment data based on the updated radio environment data.
22. A system comprising the apparatus of claim 17 and a control
server, wherein the apparatus further comprises a network interface
unit that is configured to transmit to and receive messages from
the control server over a data network, wherein the controller is
configured to send the GPS location data and radio environment data
via the network interface unit to the control server, the control
server being configured to: compare the GPS location data with
reference GPS location data, send a message to the apparatus to
enable service when the GPS location data substantially matches the
reference GPS location data and store the radio environment data as
reference radio environment data for subsequent location
verification of the apparatus.
23. The system of claim 22, wherein when the apparatus is
subsequently rebooted and starts up with service disabled, and the
controller is configured to control the radio transceiver unit to
receive wireless signals and to generate radio environment data,
send the radio environment data to the control server, wherein the
control server is configured to compare the radio environment data
with the reference radio environment data and to send a message to
the apparatus to re-enable service when the radio environment data
generated at reboot substantially matches the reference radio
environment data.
24. The system of claim 22, wherein when the control server
determines that the radio environment data generated at reboot does
not match the reference radio environment data, the control server
is configured to transmit a message to the apparatus commanding it
to capture GPS location data, and wherein the controller is
responsive thereto to control the GPS receiver unit to receive
signals from GPS satellite transmitters to produce GPS location
data, send the GPS location data to the control server, wherein the
control server is configured to compare the GPS location data
obtained at reboot with the reference GPS location data and to send
a message to the apparatus to re-enable service when the GPS
location data matches the reference GPS location data and to update
the reference radio environment data based on the radio environment
data obtained at reboot.
25. Logic encoded in one or more tangible media for execution and
when executed operable to: generate global positioning system (GPS)
location data of a radio access point device from signals received
from GPS satellite transmitters; generate radio environment data
from wireless signals received at one or more specified channels,
wherein the radio environment data represents characteristics of
the wireless signals at the one or more specified channels in a
environment of the radio access point device; compare the GPS
location data with reference GPS location data for an expected
location of the radio access point device; and when the GPS
location data substantially matches the reference GPS location
data, enabling service of the radio access point device and storing
the radio environment data to be used as reference radio
environment data for purposes of subsequent location verification
of the radio access point device.
26. The logic of claim 25, and further comprising logic that is
configured to, a period of time after enabling operation of the
radio access point device, generate updated radio environment data
from wireless signals received in the frequency band, and adjust
the reference radio environment data based on the updated radio
environment data.
27. The logic of claim 25, and further comprising logic that is
configured to, when the radio access point device is subsequently
rebooted and boots up with service disabled, generate radio
environment data from wireless signals received in the frequency
band, compare the radio environment data with the reference radio
environment data and re-enable service of the radio access point
device when the radio environment data substantially matches the
reference radio environment data.
28. The logic of claim 27, and further comprising logic that is
configured to, when it is determined that the radio environment
data does not match the reference radio environment data, generate
GPS location data from signals received from GPS satellite
transmitters, compare the GPS location data with the reference GPS
location data, re-enable service of the radio access point device
when the GPS location data matches the reference GPS location data,
and update the reference radio environment data based on the radio
environment data obtained at reboot.
29. The logic of claim 25, wherein the logic that compares the GPS
location data with the reference GPS location data and the logic
that stores the reference radio environment data resides in the
radio access point device.
30. The logic of claim 25, wherein the logic that compares the GPS
location data with the reference GPS location data and the logic
that stores the reference radio environment data resides in a
control server that is remote from the radio access point device,
and further comprising logic in the radio access point device that
is configured to send the GPS location data and radio environment
data to the control server.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to managing operations of
radio access point devices, such as femtocell access point devices,
in wireless communication networks.
BACKGROUND
[0002] Femtocell access point devices are radio access point
devices that are deployed at subscriber sites in order to improve
coverage of mobile wireless communication service (e.g., cell
phone, wireless messaging, etc.) and thereby offload the burden on
the infrastructure of the mobile service provider. Femtocell access
points are essentially cellular transceiver towers. Like cell
towers, femtocell access points operate in a licensed spectrum that
is subject to strict regulatory constraints on service providers.
For example, a femtocell access point should not transmit on a
frequency that is not licensed by a service provider in a given
location. The Federal Communication Commission (FCC) requirements
in the United States are particularly strict and a service provider
may have licensed different frequencies in different parts of the
country. As a result of this regulatory environment, femtocell
access point deployments require ongoing location verification.
[0003] Techniques to perform location verification typically
involve two mechanisms: Global Positioning System (GPS) based
location and radio network scan. GPS location techniques require a
line-of-sight from the femtocell access point device to the sky and
the GPS receiver in the femtocell access point has to "lock" to
signals from several different satellites in order to obtain an
accurate GPS location. Moreover, a GPS location procedure may
require up to 20 minutes (or longer) in order to lock to signals
from the satellites. The use of an external antenna partially
alleviates the line-of-sight issues. However, the relatively long
period of time needed to lock to the satellites is undesirable,
particularly when the femtocell access point device is rebooting
and cannot resume serving devices in the wireless network until the
location has been verified on reboot.
[0004] The radio scan function of the femtocell access point allows
it to listen to its radio environment and detect neighbor cellular
transceivers. Neighbor cellular transceiver "towers" transmit
signals that contain basic information, such as country, network
and cellular transceiver identification. At a basic level, the
radio scan function allows a femtocell access point to ascertain
that it is in the right country and in the neighborhood of the
correct "macro" cell(s). However, this information alone may not be
sufficient to determine the precise geographic location of the
femtocell access point device and the corresponding frequency on
which the femtocell access point should operate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is an example of a block diagram of a wireless
communication network in which location verification techniques
described herein are employed when enabling service of radio access
point devices.
[0006] FIG. 2 is an example of a block diagram of a radio access
point device that is configured to generate GPS location data and
radio environment data that are used in the location verification
techniques.
[0007] FIG. 3 is an example of a block diagram of a control server
that is configured to perform location verification of radio access
point devices.
[0008] FIGS. 4 and 5 illustrate examples of flow charts for logic
that is executed in the radio access point device that is
configured to participate in the location verification techniques
described herein.
[0009] FIGS. 6-8 illustrate examples of flow charts for logic that
is executed in the control server that is configured to perform the
location verification techniques described herein.
[0010] FIG. 9 is an example of a block diagram of a radio access
point device that is configured to generate GPS location data and
radio environment data and to autonomously perform the location
verification techniques described herein.
[0011] FIGS. 10-12 are examples of flow charts for logic executed
in the radio access point device that is configured to autonomously
perform the location verification techniques described herein.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0012] Techniques are provided to perform location verification of
a radio access point device. The radio access point device is
configured to receive signals from global positioning system (GPS)
satellite transmitters to produce GPS location data representing a
geographical location of the radio access point device. The radio
access point device is also configured to receive wireless signals
at one or more channels and to generate radio environment data
representing characteristics of received wireless signals at the
one or more channels in an environment or vicinity of the radio
access point device. A comparison is made between the GPS location
data and reference GPS location data for an expected location of
the radio access point device. The expected location can be
determined based on subscriber registration data. When the GPS
location data substantially matches the reference GPS location
data, service of the radio access point device is enabled and the
radio environment data is stored to be used as reference radio
environment data for purposes of subsequent location verification
of the radio access point device, which may allow future location
verification to bypass the GPS test.
[0013] Referring first to FIG. 1, a communication system 5 is shown
in which a wide area wireless communication network 10, e.g., a
wireless cellular network, is deployed. The network 10 comprises a
plurality of cellular radio transceiver "towers", two of which are
shown at 20(1) and 20(2) to serve wireless network clients, e.g.,
multiple mobile wireless handset devices, two of which are shown at
30(1) and 30(2) in FIG. 1. It should be understood that an actual
wireless network 10 may have more than two cellular radio
transceiver towers and more than two wireless client devices but
only two of each are shown in FIG. 1 for simplicity. The cellular
radio transceiver towers 20(1) and 20(2) connect to a service
provider wireless network infrastructure hub 40 that in turn
interfaces to any of a variety of telecommunication service
networks, such as the public switched telephone network (PSTN).
[0014] In order to improve coverage of the wireless network 10 and
to offload some servicing burden of the infrastructure of the
wireless network 10, a radio access point (RAP) device 50 is
deployed. A single RAP device 50 is shown in FIG. 1, but it should
be understood that there may be multiple RAP devices deployed in
different locations throughout areas where coverage is desired for
the wireless network. Depending on the size and capacity of the RAP
device 50, it may be referred to as a "femtocell" access point
device, as a picocell access point device, as a nanocell access
point device or other trade names. The RAP device 50 connects to a
provisioning management server 60 via the Internet 65. The
provisioning management server 60 (also referred to herein as a
"control server") connects to the service provider wireless network
infrastructure hub 40 via the Internet 65 and manages activation of
RAP devices 50 in the wireless network 10. Data associated with
services that are served by the RAP 50 are routed via the Internet
65 to the service provider wireless network infrastructure hub
40.
[0015] RAP devices act as cellular radio transceiver towers in that
they operate in licensed spectrum just like the larger and fixed
cellular radio transceiver towers 20(1) and 20(2). However, since
RAP devices are by their nature movable from one location to
another, deployment and service activation of RAP devices involves
location verification in order to ensure compliance with regulatory
requirements. To this end, each RAP device is equipped with the
capability to generate data representing its geographic location in
order to verify that the RAP device is operating in a location
where it is permitted to do so within the regulatory and service
provider requirements.
[0016] According to the techniques described herein, a combination
of GPS location data and radio environment data are used to verify
that a RAP device is at a proper location, and therefore may be
activated to service (transmit signals to and receive signals from)
wireless client devices, e.g., mobile handsets, of the wireless
network 10. GPS satellites are shown at 70(1)-70(K). The RAP device
50 has a GPS receiver and is capable of computing its GPS location
on earth from signals received from multiple GPS satellite
transmitters. Upon initial activation of the RAP device 50 (and
prior to enabling service for the first time), the GPS location
data determined by the RAP device 50 is used to first verify that
the RAP device is at an acceptable location. If it is determined to
be at an acceptable location based on the GPS location data, radio
environment data is scanned by the RAP device is then stored for
later use as reference radio environment data for subsequent
location verification of the RAP device, if necessary. For example,
on subsequent reboots of the RAP device 50, radio environment data
generated at reboot time is compared against the reference radio
environment data to verify the location of the RAP device 50. At
reboot, GPS location data is only used if there is a mismatch
between the radio environment data obtained at reboot and the
reference radio environment data. This avoids the need to perform
the more time-consuming GPS location procedure. In addition,
periodic or on-demand radio environment data captures are performed
for an RAP device in order to adjust or update the reference radio
environment data to account for the possible changes in the radio
environment around the RAP device. This increases the likelihood
that location verification on next reboot will not require use of
the GPS procedures.
[0017] The location verification process may be collaborative
between the RAP device 50 and the control server 60. In the
collaborative form of the location verification process, the
control server 60 stores reference GPS location data against which
the GPS location data obtained by the RAP device 50 at initial
activation (and reboot if necessary) is compared. The reference
data for GPS may be obtained when device is registered within
service provider systems, for example, based on the address were
device is expected to be deployed. The control server 60 also
stores the reference radio environment data captured by the RAP
device 50 for purposes of maintaining a reference or benchmark
(i.e., a fingerprint) against which subsequently captured radio
environment data from that RAP device is compared (such as in the
reboot scenario). The reference radio environment data is only
stored if the location of the RAP device 50 was verified using GPS
comparison. Also, in the collaborative form, the control server 60
makes the comparisons and sends messages to the RAP device to
enable or re-enable service of the RAP device.
[0018] However, in another form of the location verification
process, the RAP device 50 is configured to enable and re-enable
service autonomously. In the autonomous form, the RAP device 50 is
configured with and stores the reference GPS location data for
comparison against actual GPS location data when the RAP device
service is initially activated (or upon reboot if location
verification based on radio environment data fails), and to store
the reference radio environment data against which subsequently
captured radio environment data is compared. Also in the autonomous
form, the RAP device 50 determines on its own, without receipt of
messages from the control server 60, as to whether it is to be
enabled or re-enabled for service depending of the results of
location verification made by the RAP device 50. As explained
further hereinafter, a RAP device that is configured to operate
autonomously may be configured to contact the control server to
receive initial provisioning data that includes the reference GPS
location data for an expected location of the RAP device and
tolerance data that describes a tolerance range within which a
match to the reference GPS location and radio environment data is
to be declared.
[0019] FIGS. 2-8 pertain to the collaborative form of the location
verification process and FIGS. 9-12 pertain to the autonomous form
of the location verification process.
[0020] Turning now to FIG. 2, an example block diagram is shown of
RAP device 50 that is configured to participate in the
collaborative form of the location verification techniques
described herein. The RAP device 50 comprises a controller 100 that
serves as the primary control component of the RAP device 50. There
is a cellular modem and radio frequency (RF) transceiver unit 110
that is configured to perform the baseband and RF signal processing
required to transmit and receive over-the-air signals according to
a desired wireless communication standard that is employed in the
wireless network 10, much like the signals transmitted by the
cellular radio transceiver towers 20(1) and 20(2) shown in FIG. 1.
The cellular modem and RF transceiver unit 110 transmits signals
and receives wireless (RF) signals via the antenna 112 in order to
serve wireless client devices operating in the wireless network 10
(FIG. 1). Thus, the RAP device 50 is said to be "enabled" or
"re-enabled" for service when it has been configured or commanded
to transmit and receive wireless radio signals with respect to
wireless client devices operating in the wireless network 10. There
is also a GPS receiver 120 that receives signals from GPS satellite
transmitters via antenna 122. The controller 100 controls operation
of the cellular modem and RF transceiver 110 as well as the GPS
receiver 120. A network interface unit 130 is provided that
connects to the controller 100 and interfaces the RAP device 50 to
a data network, e.g., a local area network, that is in turn
connected to the Internet 65.
[0021] The controller 100 may, in one example, be a programmable
microprocessor or microcontroller, etc., that executes instructions
encoded in a processor readable memory medium, e.g., memory 140. To
this end, there are instructions encoded or otherwise stored in the
memory 140 for radio scan logic 150, GPS location logic 160 and
service activation and reboot logic 200 encoded or otherwise stored
in the memory 140. The controller 100 executes the radio scan logic
150 in order to control the cellular modem and RF transceiver 110
to perform a scan at one or more specified channels in order to
generate radio environment data from received wireless signals at
the one or more specified channels of interest. Examples of the
information contained in the radio environment data are described
hereinafter. Similarly, the controller 100 executes the GPS
location logic 160 to control the GPS receiver 120 to receive
signals from GPS satellite transmitters and to compute GPS location
data representing a location of the RAP device 50 on earth. The GPS
location data may comprise latitude/longitude coordinate data.
[0022] Under control of the radio scan logic 150, the controller
100 controls the cellular modem and RF transceiver 110 during a
radio scan event to extract data from received RF signals, e.g.,
received cellular signals, and to make measurements of the received
signal power, etc., for use in constructing a "fingerprint" of the
radio environment data to be used as a reference. The controller
100 executes the service activation and reboot logic 200 when the
RAP device 50 is initially powered up, is shut down and
subsequently rebooted (after initial service activation) and during
normal service to update the radio environment data. In the course
of execution the service activation and reboot logic 200, the
controller 100 also executes the radio scan logic 150 and/or the
GPS location logic 160. The service activation and reboot logic 200
is described in further detail hereinafter in conjunction with
FIGS. 4 and 5.
[0023] Turning now to FIG. 3, an example of a block diagram of the
control server 60 is described. The control server 60 may comprise
one or more server computers equipped with software to perform a
variety of management functions for RAP devices. One such
management function is to control service activation of RAP devices
by first verifying that they are located where they should be
located and thus permitted to transmit RF signals within a certain
geographical area where they should be located. In the
collaborative form of the techniques described herein, the control
server 60 is equipped to communicate with RAP devices to verify
their locations before enabling them for service and for
re-enabling RAP devices for service upon reboot as necessary. The
control server 60 comprises a data processor 300 (e.g., one or more
server computers) that stores and executes RAP location
verification logic 400. The control server 60 may comprise a data
storage device 310 that stores the reference GPS location data and
reference radio environment data for each RAP device that the
control server 60 is responsible to manage in the wireless network
10.
[0024] With reference now to FIGS. 4 and 5, the service activation
and reboot logic 200 is described. For simplicity, the logic 200 is
separated into two components, logic 210 and logic 230. FIG. 4 is a
flow chart for logic 210 and FIG. 5 is a flow chart for logic 230.
The logic 210 pertains to the functions in the RAP device 50 for
initial service activation of the RAP device and subsequent
updating of the radio environment data after initial service
activation. The logic 230 pertains to the functions in the RAP
device 50 that are performed when the RAP device is rebooted from a
shut-down mode at some time after initial service activation. There
are a variety of reasons why the RAP device may have to be
rebooted, such as power failure, software failure and repair,
hardware failure and repair, etc.
[0025] Referring first to FIG. 4, with reference also to FIGS. 1
and 2, the logic 210 is described. The logic 210 begins at 212 with
the assumption that the RAP device is not yet activated for
service. For example, the RAP device is about to be installed by a
user at a user site. When a user powers up the RAP device, the
controller 100 recognizes that it has not yet been activated and
enabled for service by the control server 60. Therefore, at 214,
the controller 100 invokes the radio scan logic 150 to perform a
radio network scan of RF signals and invokes the GPS location logic
160 to receive GPS signals and determine the GPS location of the
RAP device. In a variation of the above, the control server 60, in
response to receiving a simple boot notification message from the
RAP device 50, may send a message to the RAP device 50 instructing
it to perform the initial GPS location computation and radio
network scan. Once the RAP device performs the radio network scan
and generates radio environment data and generates GPS location
data, it sends this data to the control server 60.
[0026] The radio environment data may comprise one or more pieces
of information concerning the RF environment in the vicinity of the
RAP device 50. For example, the radio environment data may comprise
an identifier (ID) of one or more cellular radio transceiver towers
which transmit within the vicinity of RAP (e.g., ID of cellular
radio transceiver tower 20(1) and/or 20(2) shown in FIG. 1) also
known as a neighbor cell ID, ID of one or more nearby RAP devices,
a so-called "country code" extracted from a received cellular
signal from a nearby radio transceiver tower, a so-called "network
code" from a received cellular signal from a nearby radio
transceiver tower or from a mobile handset device, and frequency of
each of one or more cellular signals received from a nearby radio
transceiver tower, etc. In addition, the radio environment data may
include one or more of a scrambling code of a received cellular
signal, a regional network controller ID for a cellular radio
transceiver, a received power of a signal from a cellular radio
transceiver, an indication of transmitted power level for a signal
transmitted by a cellular radio transceiver, and transmission power
loss derived from a difference between transmitted signal power and
received signal power of a cellular signal from a cellular
transceiver tower. The transmitted power of a cellular signal may
be encoded in a field of the cellular signal. As explained above,
the cellular modem and RF transceiver 110 extracts from received
wireless signals data that is useful for the radio environment data
and also makes measurements on received signals that are useful for
the radio environment data. Below is a table that lists an example
of radio environment data that a RAP device may produce. It is to
be understood, however, that the structure of the radio environment
data is flexible and can accommodate unique wireless network
service provider requirements.
TABLE-US-00001 TABLE 1 Example of Radio Environment Data Neighbor
Country Network Frequency Receive power transmitter Cell ID Code
Code Channel strength #1 45678 310 234 256 -50 dBm #2 34561 310 235
9257 -58 dBm #3 12678 310 356 258 -62 dBm
[0027] The control server 60 receives the GPS location data and the
radio environment data from the RAP device and performs location
verification to determine whether or not to enable service the RAP
device. The process of location verification is described
hereinafter in conjunction with FIG. 6. Generally, when the control
server 60 determines that the RAP device is at a location where it
is permitted to operate, it sends, via the Internet, a message to
the RAP device instructing the RAP to enable service. Thus, at 216,
when the RAP device receives the message instructing it to enable
service, the RAP enables service at 218. If the RAP device does not
receive this message from the control server 60, the RAP device is
kept in a service disabled state as indicated at 220 and may at a
later point obtain new radio environment and GPS data and attempt
to get activation authorization from the control server 60
again.
[0028] When the RAP device 50 is enabled for service at 218, the
logic 210 essentially goes to sleep for a configurable period of
time as indicated at 219 before performing an updated radio network
scan. Alternatively, the control server 60 may send a message to
the RAP device 50 commanding it to perform a new radio network
scan. The purpose of performing the updated radio network scan is
to update the radio environment data from time to time to account
for possible changes in the RF environment surrounding the RAP
device 50. At 222, the controller 100 in the RAP device invokes the
radio scan logic 150 to perform a radio network scan of RF signals
and generates updated radio environment data that is then sent to
the control server 60 to update the reference radio environment
data maintained at the control server 60 (if necessary) for the RAP
device 50. This process of updating the radio environment data,
represented by the functions 219 and 222, is repeated periodically
as indicated by the loop back from 222 to 219 in FIG. 4, or on
demand.
[0029] In one variation to the logic 210, when the RAP device 50
generates the radio environment data, it may be configured to
generate "raw" data associated with signals received by the
cellular modem and RF transceiver 110, and to send this "raw" data
to the control server 60. The control server 60 then processes the
"raw" data to generate the radio environment data fingerprint for
the radio environment data using pieces of the raw data that are
deemed to be relevant.
[0030] In another variation to the process logic 210 shown in FIG.
4, it may be desirable to periodically repeat the location
verification functions shown at 214-220 even after service has been
enabled for the RAP device 50. This would serve as additional
location verifications that may be desired by the service provider
even after service is initially enabled at the RAP device 50. If at
one of these periodic location verification tests it is determined
that location verification fails, then service of the RAP device 50
is disabled. Further still, prior to initial service enablement of
the RAP device 50, the functions 214-220 may be repeated
periodically until service for the RAP device 50 is eventually
initially enabled.
[0031] Turning to FIG. 5, with reference also to FIGS. 1 and 2, the
logic 230 is now described. The logic 230 is configured to achieve
location verification of the RAP device 50 when, after initial
activation, it is rebooted. As indicated at 231, when rebooted the
RAP device 50 starts up with service disabled in order to enable
location verification to take place first. For example, the RAP
device 50 may have been moved while it was powered down. At 232,
when the RAP device 50 is rebooted (powered-up again), the
controller 100 is configured to recognize the reboot operation and
to invoke the radio scan logic 150 to perform a radio network scan
in order to generate radio environment data and to send the radio
environment data to the control server 60 in a reboot request
message. Alternatively, the RAP device 50 may simply contact the
control server 60 upon reboot notifying it of reboot and the
control server 60 may instruct the RAP device to perform the radio
scan. Once the control server 60 receives radio environment data
from the RAP device, the control server 60 verifies the location of
the RAP device by comparing the radio environment data with the
stored reference radio environment data to determine whether there
is a substantial match. Thus, at 234, if the RAP device receives a
message instructing it to re-enable service, then the RAP device
re-enables service at 236 and can resume serving wireless client
devices in the wireless network 10.
[0032] When the RAP device does not receive a message commanding it
to re-enable service, then at 238, the controller 100 waits to
receive a message from the control server 60 that commands it to
perform a GPS location determination to generate GPS location data.
Until such a command message is received, the RAP device 50 is kept
disabled as indicated at 239. When the RAP device 50 receives the
message to capture GPS location data, at 240 the controller 100 in
the RAP device invokes the GPS location logic to generate GPS
location data and sends the GPS location data to the control server
60. In a variation, the GPS location function at 240 may be invoked
automatically by the RAP device 50 when it does not receive a
message instructing it to re-enable service based on radio
environment data. The control server 60 compares the GPS location
data with the reference GPS location data for the RAP device 50 and
if they substantially match, sends a control message to the RAP
device 50 to re-enable service. At 241, the controller 100 waits
for and responds to the message from the control server 60 to
re-enable service, and at 236, re-enables RAP service. Otherwise,
RAP service is kept disabled as indicated at 242, in which case the
reactivation process described in FIG. 5 may be repeated at a later
point in time.
[0033] Reference is now made to FIGS. 6-8 for a description of the
RAP location verification logic 400 in the control server 60. For
simplicity, the RAP location verification logic 400 is separated
into three logic components: logic 410 for location verification
for initial service activation of a RAP device, logic 430 for
storing updated radio environment data, and logic 450 for location
verification at reboot (RAP service re-enablement).
[0034] Referring first to FIG. 6, with reference also to FIGS. 1
and 3, the logic 410 for location verification upon initial service
activation of an RAP device is now described. At 412, the control
server 60 receives an initial service activation request message
from a RAP device and the initial service activation request
message comprises GPS location data captured by the RAP device and
radio environment data captured upon initial power up of the RAP
device. Alternatively, control server 60 receives a message with
boot notification from the RAP device 50, recognizes that this is
initial activation and sends a control message to RAP device to
request radio environment and GPS data. At 414, the control server
60 compares the GPS location data with stored reference GPS
location data for the RAP device that is requesting activation. The
stored reference GPS location data may be determined from an
expected location of the RAP device when it was sold or distributed
to a user or customer, such as from an expected location determined
based on user/subscriber registration data (such as a postal
address).
[0035] When it is determined that the GPS location data captured by
the RAP device substantially matches the reference GPS location
data, then location verification is said to have passed, and at 418
the control server 60 stores the radio environment data as
reference radio fingerprint data for that RAP device. At 420, the
control server 60 sends a message to the RAP device to enable
service of the RAP device. When used herein, "substantially or
sufficiently match" is meant to include a complete match as well as
a match within a specified or configurable tolerance range. The
degree to which GPS location must match can be controlled via
administrative configuration made at the control server 60. As
indicated at 416, the control server 60 does not send a message
enabling service of the RAP device when the GPS location data
comparison fails at 414.
[0036] Thus, at 418, the control server 60 stores data for each RAP
that passes location verification upon initial activation. Table 2
below shows examples of data stored at the control server 60 for
RAP device assigned identifier 3576421 and for RAP device assigned
identifier 7745531.
TABLE-US-00002 TABLE 2 RAP Location and Radio environment data RAP
ID 3576421 Reference (Expected) GPS Location Data Latitude:
45'56''32 N Longitude: 33'23''12 W Reference Radio Environment Data
Neighbor Cell ID: 34564 Receive Power: -98 dBm Neighbor Cell ID:
44321 Receive Power: -63 dBm RAP ID 7745531 Reference (Expected)
GPS Location Data Latitude: 15'66''12 N Longitude: 26'23''55 W
Reference Radio Environment Data Neighbor Cell ID: 24364 Receive
Power: -82 dBm Neighbor Cell ID: 14121 Receive Power: -45 dBm
[0037] Turning to FIG. 7, again with continued reference to FIGS. 1
and 3, the logic 430 for storing updated radio environment data is
now described. This logic 430 is invoked when a RAP device captures
updated radio environment data. As explained above, a RAP device
may be configured to periodically capture updated radio environment
data or the control server 60 may command the RAP device to capture
updated radio environment data. At 432, the control server 60
receives updated radio environment data from a RAP device that has
already been enabled for service. At 434, the control server 60
determines which RAP has sent updated radio environment data (based
on a RAP identifier contained in the message with the updated radio
environment data) and compares the updated radio environment data
with previously stored reference radio environment data for that
particular RAP. At 436, when it is determined that the difference
between the updated radio environment data and the previously
stored reference radio environment data is less than a threshold,
then the reference radio environment data is not adjusted with the
updated radio environment data. On the other hand, when the
difference is greater than a threshold, then at 440 the updated
radio environment data is used to adjust the reference radio
environment data. The existing reference radio environment data may
be adjusted by a complete overwrite with the updated radio
environment data, by adding new pieces of information in the
updated radio environment data that that are not contained in the
reference radio environment data or by changing one or more pieces
of information in the reference radio environment data with data in
the updated radio environment data. In this way, when there are
substantial enough changes in the RF environment of an RAP device,
the corresponding changes in the radio environment data can be
reflected in the reference radio environment data so that future
location verification of the RAP device can take these changes into
account. Said another way, the reference radio environment data is
adjusted based on the updated radio environment data depending on a
difference between the updated radio environment data and the
reference radio environment data. The reference data need not be
updated every time it is reported from an activated RAP device with
verified location. However, in one form it may be desirable to
bypass the check at 436 and update the reference environment data
regardless of the degree of difference between the updated radio
environment data and the current reference environment data. Thus,
the functions at 434 and 436 are optional and the logic may go
directly from 432 to 440.
[0038] Turning now to FIG. 8, the logic 450 in the control server
dedicated to location verification for reboot and service
re-enablement is now described. At 452, the control server 60
receives a reboot request message from a RAP device containing
radio environment data captured by the RAP device at the time of
reboot. Alternatively, the request may not contain radio
environment data and control server 60 may send a control message
to RAP device to request this data. At 454, the control server
compares the radio environment data in the reboot request message
with the reference radio environment data for the RAP device and
when there is a substantial match at 456, the control server 60
sends a message to the RAP device to re-enable service of the RAP
so that it can resume serving wireless client devices in the
wireless network. Again, "substantial match" as used herein in
connection with the comparison between captured radio environment
data at reboot and the reference radio environment data is meant to
include a complete match as well as a match within a certain
tolerance range. Moreover, a partial match between the radio
environment data at reboot with the reference radio environment is
also possible. For example, a change in received power strength
from neighbor cellular towers can be approximately translated into
a distance traveled by the RAP device since the last reference was
obtained. A comparison of radio environment data can allow a
certain range of receive power variation (e.g. 6 dBm) from the
prior benchmark (reference environment data). Thus, the comparison
of the radio environment data at reboot with the reference radio
environment data may involve comparing a portion of the radio
environment data generated at reboot with a corresponding portion
of the reference radio environment data.
[0039] Otherwise, when there is not a match at 454, the control
server 60 does not send a message to re-enable operation of the RAP
device and at 460, the control server 60 sends a message to the RAP
requesting it to capture GPS location data. At 462, the control
server 60 receives a message from the RAP device 50 containing the
GPS location data. At 464, the control server 60 compares the GPS
location data received from the RAP device with the reference GPS
location data for that RAP device. When there is a substantial
match, at 466 the control server 60 sends a message to the RAP
device to re-enable its operation. Then, at 468, the control server
60 updates the reference radio environment data based on the radio
environment data obtained by the RAP at reboot. When at 464 it is
determined that the GPS location data received from the RAP device
and the reference GPS location data do not substantially match,
then the control server 60 does not send a message re-enabling
operation of the RAP device as indicated at 469.
[0040] Referring now to FIG. 9, a RAP device 50' is shown that is
configured to autonomously perform location verification according
to the techniques described herein. The RAP device 50' does this
autonomously because, except for acquiring basic provisioning data,
it does not need to interact with the control server 60 to enable
or re-enable service. The RAP device 50' is similar to RAP device
50 shown in FIG. 2, except that it has autonomous service
activation and reboot logic 500 instead of logic 200 shown in FIG.
2 for RAP device 50. For simplicity, the autonomous service
activation and reboot logic 500 is broken down into three
components: initial service activation and location verification
logic 510, radio environment data update logic 530 and reboot
re-enablement and location verification logic 550.
[0041] Referring to FIG. 10, with reference also to FIG. 9, the
initial activation and location verification logic 510 is
described. The RAP device 50' is assumed to be in a service
disabled state as shown at 512. In one form, when the RAP device
50' is powered up, at 514 it sends a message to the control server
60 requesting provisioning data to allow the RAP device 50' to
perform location verification for initial service enablement and
after subsequent reboots. The provisioning data may comprise
reference GPS location data for an expected location of the RAP
device 50' and tolerance data that describes a tolerance range
within with a match to the reference GPS and/or radio environment
location data is to be declared. The memory 140 of the RAP device
50' stores the reference GPS location data and tolerance settings.
At 516, the RAP device 50' receives the provisioning data from the
control server 60. At 518, the RAP device 50' invokes the radio
scan logic 150 to generate radio environment data and invokes the
GPS location logic 160 to compute GPS location data from received
GPS signals. At 520, the controller compares the GPS location data
captured at 518 with the reference GPS location data to determine
whether there is a substantial match, and if so, then at 522 the
controller enables service of the RAP device 50'. Otherwise, when
GPS location data captured at 518 does not substantially match the
reference GPS location data, service of the RAP device 50' is kept
disabled as indicated a 524.
[0042] At 526, the controller 100 stores in the memory 140 the
radio environment data generated at 518 as reference radio
environment data to be used for future location verification
purposes, e.g., at reboot, as described hereinafter.
[0043] Table 3 below shows an example of the data that would be
stored in RAP device 50'.
TABLE-US-00003 TABLE 3 GPS Location Data and Radio Environment Data
Stored in Autonomous RAP Reference (Expected) GPS Location Data
Latitude: 45'56''32 N Longitude: 33'23''12 W GPS Tolerance Radius
1000 meters Reference Radio Environment Data Neighbor Cell ID:
34564 Receive Power: -98 dBm Neighbor Cell ID: 44321 Receive Power:
-63 dBm Radio Environment Data Power Variance 6 dBm Tolerance
[0044] As explained above in connection with FIG. 4, it may also be
desirable to periodically repeat the location verification
functions shown at 514-522 even after service has been enabled for
the RAP device 50'. This would serve as additional location
verifications that may be desired by the service provider. If at
one of these periodic location verification tests it is determined
that location verification fails, then service of the RAP device
50' is disabled. Further still, prior to initial service enablement
of the RAP device 50', the functions 514-522 may be repeated
periodically until service for the RAP device 50' is eventually
initially enabled.
[0045] Turning now to FIG. 11 with reference to FIG. 9, the radio
environment data update logic 530 is described. After the RAP
device 50' is enabled for service, the logic 530 is put into a
sleep mode for a configurable time period as indicated at 532. At
536, the RAP performs a radio network scan to generate updated
radio environment data. At 538, the controller 100 compares the
updated radio environment data with the stored reference radio
environment data. At 540, the difference between the updated radio
environment data and the reference radio environment data is
compared with a threshold. When the difference is greater than the
threshold, then at 542 the updated radio environment data is
adjusted (either by overwriting with the updated radio environment
data, adding new pieces of information or changing existing
information) for location verification in the future. When the
difference is not greater than the threshold, then as indicated at
544, the reference radio environment data is not adjusted with the
updated radio environment data. That is, the controller 100 in RAP
device 50' adjusts the reference radio environment data based on
the updated radio environment data depending on a difference
between the updated radio environment data and the reference radio
environment data. The process of updating the radio environment
data may be repeated periodically. Alternatively, the RAP device
50' always stores the updated radio environment data as indicated
by the dotted arrow from 536 to 542 in FIG. 11.
[0046] Reference is now made to FIG. 12, with continued reference
to FIG. 9, for a description of the reboot location verification
logic 550. The controller 100 in the RAP device 50' invokes the
reboot location verification logic 550 when the RAP device 50' has
shut down and needs to reboot. After reboot, the RAP device 50'
powers up with service disabled because location verification of
the RAP device 50' must be made before allowing it to begin
transmitting RF signals as indicated at 552. Upon reboot, the
controller 100 invokes the radio scan logic 150 to perform a radio
network scan and to generate radio environment data. At 556, the
controller 100 compares the radio environment data generated at
reboot with the stored reference radio environment data to
determine whether they sufficiently match. When a match is
determined at 556, then at 558 the controller 100 re-enables
service of the RAP device 50'. In addition, the controller 100 may
update the reference radio environment data with the radio
environment data obtained by the RAP device 50' at reboot.
[0047] On the other hand, when a match is not found at 556, then at
560, the controller 100 invokes the GPS location logic to generate
GPS location data from received GPS signals. At 562, the controller
100 compares the GPS location data with the stored reference GPS
location data. When a match is found at 562, the controller
re-enables service of the RAP device 50' at 558. Otherwise, the
controller 100 keeps service of the RAP device 50' disabled as
indicated at 564 and attempt to perform the logic depicted in FIG.
12 again at a later time.
[0048] Thus, the autonomous RAP device 50' can perform location
verification on its own at initial service activation and also at
reboot to enable or re-enable, as the case may be, service of the
RAP device 50'. When the RAP device 50' stores data for later
comparison, it should be understood that such data storage is made
into memory that persists after reboot, i.e., non-volatile
memory.
[0049] While the foregoing description refers to verifying the
location of an RAP device for purposes of enabling or re-enabling
service of the RAP device, this is not meant to be limiting.
Another application of the location information is to determine and
assign to the RAP device parameters which may be unique to a
specific location, such as the frequency on which it is to transmit
wireless signals for serving mobile communication handsets in the
wireless communication network. Thus, after the location of the RAP
device is verified, the control server 60 (FIG. 1) may transmit a
message indicating the frequency on which the RAP device should
transmit in the wireless network based on the location of the RAP
device. Still another application may involve configuring the RAP
device with a list of candidate parameters for it to choose
depending on specific location. For example, more than one
potential frequency of operation may be provided to RAP. The RAP
device would then configure itself to use a particular frequency
that depends on where it is located, and only after verifying its
location.
[0050] The collaborative and autonomous version of the location
verification process described herein both have the advantage of
reducing reliance on GPS location procedures. The radio network
scan is configured to finish in a predictable amount of time and
usually much faster and more reliably than it would take to obtain
a GPS lock and produce GPS location data. Unlike GPS, the radio
network scan does not depend on reasonable line-of-sight to the
sky. Therefore, the radio environment data can be used as a
shortcut for location verification once the GPS location
coordinates have been initially verified. The radio environment
data is stored for future location verification. Use of the radio
network scan in this manner reduces reliance on GPS for location
verification of the RAP device. However, GPS may still be needed
during reboot if there is a substantial radio environment data
mismatch and in other scenarios as the ultimate authority on
absolute position of RAP device.
[0051] Although the apparatus, system, and method are illustrated
and described herein as embodied in one or more specific examples,
it is nevertheless not intended to be limited to the details shown,
since various modifications and structural changes may be made
therein without departing from the scope of the apparatus, system,
and method and within the scope and range of equivalents of the
claims. Accordingly, it is appropriate that the appended claims be
construed broadly and in a manner consistent with the scope of the
apparatus, system, and method, as set forth in the following
claims.
* * * * *